New Vitamin D and Calcium Dietary Reference Intakes from Institute of Medicine

[salvorhardin]

From Dr. Harriet Hall's post on Science Based Medicine (bolding mine):

I’ve had a lot of inquiries about “is this information trustworthy?” and “how much vitamin D should I be taking?” I’ve been telling people that I didn’t know, that recent findings will soon result in new recommendations, and I’ve been eagerly awaiting the new guidelines. Now we have them, thanks to the IOM. They are not what most of us anticipated. Since so many doctors had been advocating higher levels to prevent things like cancer, I thought official recommended intake levels would go up; instead, they went down.

The IOM was asked by the US and Canadian governments to assess the current data on health outcomes associated with calcium and vitamin D. They formed a committee of experts who did an exhaustive review of over 1000 studies and listened to testimony from scientists and stakeholders. Their report, issued on 11/30/2010, concluded that the evidence supported a role for these nutrients in bone health but not in other health conditions, that the majority of the American and Canadian population is getting enough of both vitamin D and calcium, and that there is emerging evidence that an excess of these nutrients may be harmful. Based on that evidence, they established new Dietary Reference Intakes (DRIs) for vitamin D and calcium. They acknowledged exceptions and areas of uncertainty.

...

The IOM report explains

the measurements, or cut-points, of sufficiency and deficiency used by laboratories to report results have not been set based on rigorous scientific studies, and no central authority has determined which cut-points to use. A single individual might be deemed deficient or sufficient, depending on the laboratory where the blood is tested. The number of people with vitamin D deficiency in North America may be overestimated because many laboratories appear to be using cut-points that are much higher than the committee suggests is appropriate.

Calcium supplements, long recommended to prevent osteoporosis, have been associated with heart attacks in postmenopausal women, but only in those who took it without the recommended addition of vitamin D. There are concerns that excess calcium might cause kidney stones and other adverse effects. The IOM found that most people get enough calcium from their diet, with the exception of girls ages 9-18, and that postmenopausal women who take supplements may be getting too much calcium. Once intakes exceed 2000 mg a day, the risk for harm increases.

Source: http://www.sciencebasedmedicine.org/?p=8725

[Mojorabbit]

1. THis is totally opposite

of what I thought was going to happen.There is a ton of research on medline which says otherwise.

[hlthe2b]

2. Yes... and this is one IOM report that will be reversed...

Given that they looked only at bone health endpoints, failed to include the 14 most noted vitamin D researchers (who DO NOT agree with their findings) as well as the premiere nutritional experts, including Walter Willett. And magnesium, the third (synergistic) leg of healthy bone development, and a nutrient we know is deficient in many diets, is not even discussed.

I have always been a strong supporter of IOM consensus panels; but I have deep qualms about this one. I, for one, will NOT be reducing my vitamin D supplementation levels; nor are any other primary care providers that I am aware of at this juncture. I regret that this has happened, since it will reduce public confidence.

[BanzaiBonnie]

3. I'd prefer they give us something more on the optimum

ratio for calcium, magnesium and vitimin D.

I'm taking 4000 IUs of D a day and am finally starting to feel alive. Before, I would get up in the morning(5AM), putter around for a couple of hours and then be exhausted. I would have to lie down and sleep for at least an hour before I could do anything else. Pitiful. Doc say my thyroid was "normal". I did a whole month of taking my temp three times a day and the drop in my temp coincided with that time I was exausted. One time my second temp of the day was 95.3 Scary and weird.

I have my PCP check my D levels every 6 months now just to make sure I'm not overdoing it. So far, so good.


I tend to suspect reports that clash with my own experience because I believe there are those who want us to be dependent on big pharma. And vitimin D is not expensive.

[glitch]

6. That's the problem with reductionist science.

They pull out one piece and study it in one area and make broad recommendations based on that.

Very old-fashioned method, even for "science-based".

Agreed on considering magnesium in the mix, adding that combination made a big difference in my health too.

Bones aren't the only reason to take calcium/magnesium/D3 supplements. I take them for my heart and nervous system as well.

[salvorhardin]

4. Dr. Hall clarifies her statement that intake levels went down

Commenter dougsmith said:

Thanks, Harriet, for the informative and balanced report. I was unsure about this point you made: “I thought official recommended intake levels would go up; instead, they went down.”

I believe the recommended intake levels went up. They used to be 200 IU/day up to age 50, now are 600 IU/day, a tripling.

Also the safe upper bound basically doubled from 2,000 IU/day to 4,000 for most age groups.

http://www.webmd.com/diet/news/20101129/guidelines-increase-vitamin-d

Harriet Hall said:

@dougsmith
I said “I thought official recommended intake levels would go up; instead, they went down.”

The IOM recommendations are a little higher than the previous RDA, but many experts had been recommending doses higher than the RDA. I was thinking of them. The way I used the word “official” was probably misleading.

Based on everything I had read, I had been taking 800 IU of vitamin D a day (I’m 65) and had been wondering if I should up the dose. The IOM report convinced me not to.

[HuckleB]

5. Thanks for the additional information! -eom-